Center assembly including oil reservoir for machine tools

Abstract

A center assembly comprising a center and an oil reservoir, the oil reservoir having a leg extending from its lower wall and formed with a bore extending therethrough and with an oil passage having a lower end opened to the bore and an upper end opened in the inner surface of the lower wall of the oil reservoir, the center fitting in the bore and being formed with an oil channel having one end opened in the outer peripheral surface of a cylindrical body portion of the center and in register with the lower end opening of the oil passage in the leg, the oil channel having the other end opened in a conical front end of the center in the vicinity of its extremity. The lubricant in the oil reservoir flows through the oil passage and channel to the front end of the center to lubricate the front end and the inner surface defining the center hole of work.

I claim: 
     
       1. A center assembly for machine tools comprising in combination: (a) a center (1) with a cylindrical body portion and a conical front end portion;   (b) an oil reservoir (8) with a cover and a bottom wall disposed above said center (1) having a leg (11) extending from its bottom wall and formed with a first bore (12) extending therethrough and with an oil passage (10) having a lower end opened to the bore (12) and an upper end opened in the inner surface of said bottom wall, said center (1) being rotatably coupled to said bore (12), a pump (52) to prevent clogging in said oil reservoir (8) including a vertical second bore (67) in said leg (11), a plunger (54) slidable in said vertical second bore (67) communicating with said oil passage (10), a spring (57) coupled to and upwardly biasing said plunger (54), and, a handle rod (53) integral with the plunger (54) extending outward through said reservoir cover;   (c) an oil channel (17) extending approximately along the geometric central line of said conical front end, said oil channel having one end opened to the outer peripheral surface of said cylindrical body portion in register with the lower end opening of said oil passage (10) and the outer end opened in said conical front end portion in the vicinity of its end; and,   (d) a downward biased needle valve coupled for opening and closing said oil passage upper end, said needle valve having:   a valve seat (32) fixedly fitted in the upper end opening of the oil passage (10), a guide tube (34) having a lower end bearing on the valve seat and an upper end projecting outward through said cover, an annular cap (41) secured to the upper end of the guide tube (34), a needle valve element (42) vertically slidably housed in the guide tube (34) and having an upper end extending outward from the guide tube through the annular cap, a spring (43) for downwardly biasing the needle valve element and a tiltable knob (45) pivoted to the upper end of the needle valve element to raise and lower the valve element.   
     
     
       2. A center assembly as defined in claim 1, wherein the leg has a threaded hole radially extending through the peripheral wall defining the first bore, and a setscrew is screwed into the threaded hole to lock the center to the oil reservoir. 
     
     
       3. A center assembly as defined in claim 1 wherein a strainer divides the interior of the oil reservoir into two compartments, one compartment being provided with an oil inlet, the other compartment having the upper end opening of the oil passage.